json-lib使用

一、资源链接：
http://json-lib.sourceforge.net/
http://ezmorph.sourceforge.net/
http://morph.sourceforge.net/
http://www.json.org/javadoc/org/json/package-summary.html

二、例子

public class JsonUtil {
	/**
	 * 从一个JSON 对象字符格式中得到一个java对象 说明：Bean的无参构造函数一定要写, 否则会报:
	 * net.sf.json.JSONException: java.lang.NoSuchMethodException
	 * 
	 * @param jsonString
	 * @param pojoCalss
	 * @return
	 */
	public static Object getObjectFromJsonString(String jsonString,
			Class pojoCalss) {
		Object pojo;
		JSONObject jsonObject = JSONObject.fromObject(jsonString);
		pojo = JSONObject.toBean(jsonObject, pojoCalss);
		return pojo;
	}

	/**
	 * 将java对象转换成json字符串
	 * 
	 * @param javaObj
	 * @return
	 */
	public static String getJsonStringFromObject(Object javaObj) {
		JSONObject json;
		json = JSONObject.fromObject(javaObj);
		return json.toString();
	}

	/**
	 * 从json HASH表达式中获取一个map
	 * 
	 * @param jsonString
	 * @return
	 */
	@SuppressWarnings("unchecked")
	public static Map getMapFromJsonString(String jsonString) {
		JSONObject jsonObject = JSONObject.fromObject(jsonString);
		Iterator keyIter = jsonObject.keys();
		String key;
		Object value;
		Map valueMap = new HashMap();
		while (keyIter.hasNext()) {
			key = (String) keyIter.next();
			value = jsonObject.get(key);
			valueMap.put(key, value);
		}
		return valueMap;
	}

	/**
	 * 从Map对象得到Json字串
	 * 
	 * @param map
	 * @return
	 */
	public static String getJsonStringFromMap(Map map) {
		JSONObject json = JSONObject.fromObject(map);
		return json.toString();
	}

	/**
	 * 从json字串中得到相应java数组
	 * 
	 * @param jsonString
	 *            like "[\"李斯\",100]"
	 * @return
	 */
	public static Object[] getObjectArrayFromJsonString(String jsonString) {
		JSONArray jsonArray = JSONArray.fromObject(jsonString);
		return jsonArray.toArray();
	}

	/**
	 * 将list转换成Array
	 * 
	 * @param list
	 * @return
	 */
	public static Object[] getObjectArrayFromList(List list) {
		JSONArray jsonArray = JSONArray.fromObject(list);
		return jsonArray.toArray();
	}

	/**
	 * 用JSONStringer构造一个JsonString
	 * 
	 * @param m
	 * @return
	 */
	public static String buildJsonString(Map m) {
		JSONStringer stringer = new JSONStringer();
		stringer.object();
		for (Object key : m.keySet()) {
			stringer.key((String) key)
				.value((String)m.get(key));
		}
		stringer.key("phone");
		//begin nesting a array
		stringer.array();
		stringer.value("13998098000");
	    stringer.value("8765432");
	    //nestring object in array
	    stringer.object();
	    stringer.key("ppcall");
	    stringer.value(53881); 
	    stringer.endObject();
	    stringer.value("13990980980");
	    //end nesting a array
	    stringer.endArray();
	    
		stringer.endObject();
		return stringer.toString();
	}

	public static void printMap(Map map) {
		for (Object key : map.keySet()) {
			System.out.println(key + ":" + map.get(key));
		}
	}

	public static void main(String[] args) {
		Map m = new HashMap() {
			{
				put("JSon", "HelloWorld");
				put("Flex", "Ok");
			}
		};
		System.out.println(buildJsonString(m));
		System.out
				.println(new JSONStringer().object().key("JSON").value(
						"Hello, World!").key("Flex").value("OK").endObject()
						.toString());
	}
}

说明：json依赖包（commons-collections.jar，commons-lang-2.X.jar，ezmorph-1.0.X.jar）